The working
- 1. Pitch multiplier√(1 + (12 ÷ 12)²)× 1.414
- 2. Roof anglearctan(12 ÷ 12)45.0°
- 3. Roof surface2,000 sq ft footprint × 1.414 (12/12 pitch multiplier)2,828 sq ft
- 4. Squares to order2,828 ÷ 100 = 28.3 squares, + 10% waste (gable roof)31.1 squares
- 5. Installed2,828 sq ft × $4–$6 per sq ft (architectural asphalt shingles, HomeGuide, Nov 7, 2025)$11,314 – $16,971
- 6. Tear-off2,828 sq ft × $1–$3 per sq ft to remove one layer (HomeGuide)$2,828 – $8,485
- 7. PermitFlat fee, set locally (HomeGuide, Fixr)$100 – $500
- 8. Installed totalSum, rounded to $100 under $10,000 and $500 above$14,000 – $26,000
Prices are published national installed ranges (mostly HomeGuide, updated Nov 7, 2025), the same ones the roof cost calculator uses, for a straightforward re-roof with one old layer torn off. They are not adjusted for your state; the calculator can do that. Decking repairs, access, steep or cut-up roofs and the contractor all move the final price, so get at least two written quotes.
Squares and the materials list come from the same math as the roof calculator, which works them out for your own measurements.
12/12 roof by footprint
| Footprint | Roof surface | Squares | Asphalt shingles | Standing-seam metal |
|---|---|---|---|---|
| 1,000 sq ft | 1,414 sq ft | 14.1 | $7,200 – $13,000 | $14,000 – $27,500 |
| 1,500 sq ft | 2,121 sq ft | 21.2 | $10,500 – $19,500 | $21,500 – $41,000 |
| 2,000 sq ft | 2,828 sq ft | 28.3 | $14,000 – $26,000 | $28,500 – $54,000 |
| 2,500 sq ft | 3,536 sq ft | 35.4 | $18,000 – $32,500 | $35,500 – $67,500 |
| 3,000 sq ft | 4,243 sq ft | 42.4 | $21,500 – $38,500 | $42,500 – $81,000 |
Compared with nearby pitches (2,000 sq ft footprint)
| Pitch | Angle | Area multiplier | Walking it | Asphalt shingles |
|---|---|---|---|---|
| 10/12 | 39.8° | × 1.302 | Very steep | $13,000 – $24,000 |
| 11/12 | 42.5° | × 1.357 | Very steep | $13,500 – $25,000 |
| 12/12 | 45.0° | × 1.414 | Very steep | $14,000 – $26,000 |
From about 7/12 or 8/12 most crews use roof jacks and harnesses, and many contractors add a steep-roof charge that published per-square-foot ranges do not show.
Did hail hit your area? Insurance often covers hail damage. Check hail history for your city, with storm reports back to 1955.
Questions people ask
What is the multiplier for a 12/12 roof?
1.414. Multiply the footprint by it to get the sloped roof area: 2,000 sq ft of footprint is 2,828 sq ft of roof.
What angle is a 12/12 pitch?
45.0 degrees. It rises 12 inches for every 12 inches across.
Is a 12/12 roof walkable?
Very steep: do not walk it. Staging and fall arrest only. Work is done from roof jacks, staging or lifts with personal fall arrest.
More roof cost guides
- Flat roof cost and squares
- 3/12 pitch roof: multiplier, angle and cost
- 4/12 pitch roof: multiplier, angle and cost
- 5/12 pitch roof: multiplier, angle and cost
- 6/12 pitch roof: multiplier, angle and cost
- 7/12 pitch roof: multiplier, angle and cost
- 8/12 pitch roof: multiplier, angle and cost
- 9/12 pitch roof: multiplier, angle and cost
- 10/12 pitch roof: multiplier, angle and cost
- Roof cost for a 1,000 sq ft house
- Roof cost for a 1,200 sq ft house
- Roof cost for a 1,500 sq ft house
- Roof cost for a 1,800 sq ft house